Adding a way to associate Android Activities with PlatformWindowAndroid

ui/aura/client/aura_constants.cc

Index: ui/aura/client/aura_constants.cc
diff --git a/ui/aura/client/aura_constants.cc b/ui/aura/client/aura_constants.cc
index 18733c7d3b17e0befdc6fe0ceb694350c09f3a63..7195ce2cca70861d29ced9f2c614346d9cfbff64 100644
--- a/ui/aura/client/aura_constants.cc
+++ b/ui/aura/client/aura_constants.cc
@@ -7,6 +7,16 @@
 #include "ui/aura/window_property.h"
 #include "ui/gfx/geometry/rect.h"
 
+#if defined(OS_ANDROID)
+#include "base/android/jni_weak_ref.h"
+#endif
+
+
+#if defined(OS_ANDROID)
+DECLARE_WINDOW_PROPERTY_TYPE(JavaObjectWeakGlobalRef*);
+#endif
+
+
 DECLARE_EXPORTED_WINDOW_PROPERTY_TYPE(AURA_EXPORT, bool)
 DECLARE_EXPORTED_WINDOW_PROPERTY_TYPE(AURA_EXPORT, ui::ModalType)
 DECLARE_EXPORTED_WINDOW_PROPERTY_TYPE(AURA_EXPORT, gfx::Rect*)
@@ -20,6 +30,11 @@ namespace client {
 
 // Alphabetical sort.
 
+#if defined(OS_ANDROID)
+DEFINE_OWNED_WINDOW_PROPERTY_KEY(
+    JavaObjectWeakGlobalRef, kActivityForRootWindow, nullptr);
+#endif
+
 DEFINE_WINDOW_PROPERTY_KEY(bool, kAlwaysOnTopKey, false);
 DEFINE_WINDOW_PROPERTY_KEY(bool, kAnimationsDisabledKey, false);
 DEFINE_WINDOW_PROPERTY_KEY(bool, kCanMaximizeKey, false);